help me decide which one

Gigabyte M27QX or AOC Q27G3XMN, is there a noticeable difference in 180hz and 240hz? also if i do get the AOC, and I lower the resolution on display settings lets say 1080p, would I be able to get more hertz out of it or would it be 180hz as its in 1440p native? I’m looking for a monitor for competitive gaming but also good triple AAA games.